This invention relates to a trigger sprayer having a nozzle cap adapted to selectively discharge in the form of a spray or a foam. More specifically, this invention relates to such a nozzle cap adapted rotated to connect either a spray orifice or a foam orifice on the cap with a liquid source from the trigger pump.
The prior art is replete with trigger sprayers of various types. An example is disclosed in the McKinney U.S. Pat. No. 4,161,288 wherein the pump comprises a vertically disposed cylinder having a piston stroking as a trigger lever is pulled back and forth. This pumps the liquid from an attached container out a delivery tube to a nozzle.
Typically, trigger sprayers are provided with a nozzle including a rotatable nozzle cap. The delivery tube from the pump usually terminates in a bushing and the cap snaps over the bushing. The delivery tube passes the liquid toward the front end of the cap where it is usually introduced tangentially into a so-called xe2x80x9cswirl chamber xe2x80x9d on the rear face of the front end of the cap. In the chamber the liquid increases in angular velocity as it swirls toward the orifice and finally discharges in the form of a spray cone.
A shut-off valve may be provided between the bushing and nozzle cap wherein channels in the respective parts align in use, but the flow may be cut off by rotating the cap to an xe2x80x9coffxe2x80x9d position wherein the channels do not align.
In some sprayers the orifice and swirl chamber have been offset from the axis or the cap. In the Hayes U.S. Pat. No 4,247,048, for instance, the orifice is offset and the discharge may selectively be in the form of a stream or a spray, depending on the depth of the channel on the delivery tube where it communicates with the swirl chamber.
In U.S. Pat. No. 5,664,732 to Smolen, Jr. et al two spray orifices on the cap are diametrically opposed and offset from the axis of the cap. The cap rotates on the nozzle bushing which has a liquid supply on its front face offset from the axis. The separate orifices on the cap produce different spray patterns when connected to the supply.
The concept of a foaming sleeve surrounding the spray cone emitting from a trigger pump orifice is disclosed in the Shay U.S. Pat. No. 4,669,665. Here the cone engages the inside of the foaming sleeve, mixes with air, and discharges as a foam.
The further Shay U.S. Pat. No. 4,768,717 issued Sep. 6, 1988 teaches the idea of introducing air inwardly about the outside of a foaming sleeve to the rear end of the sleeve to enhance the foaming.
A number of prior patents have suggested means in a trigger sprayer for selecting either a foam or a spray type discharge. An example is disclosed in the Shay U.S. Pat. No. 4,767,060 wherein a foaming collar is reciprocally mounted on an annular support extending forward from the nozzle. The sleeve can be moved into either a forward position wherein it is engaged by the emitting spray cone to produce foam, and a rearward position adjacent the orifice wherein the collar is not contacted by the spray, and the discharge is in the form of a spray.
A further disclosure of a selectable spray or foam discharge is found in the Corsette U.S. Pat. No. 4,779,803 wherein a centrally apertured plate has a plurality of rearward legs which telescope into the nozzle cap about the orifice. The plate is movable as the legs slide into the cap or out from it. The plate can be set in a position where the aperture is adjacent the orifice and does not interfere with the spray or is away from the orifice, forward of it, and is impacted by the spray to produce a foam.
More recently foam/spray discharge selectability is disclosed in the Tasaki et al U.S. Pat. No. 5,344,078 and the Foster et al U.S. Pat. No. 5,767,385. In these patents a foaming sleeve or bore is pivotally attached to the side of the nozzle cap on an axis generally perpendicular to the orifice axis so that it can be swung down from an idle position to close to the orifice so that the spray from the orifice contacts the sleeve and a foam discharge is produced.
The pending application Ser. No. 09/753,648 filed Jan. 3, 2001 assigned to our assignee discloses a trigger sprayer having a sprayer/foamer selector wheel in front of the nozzle cap.
The invention is a trigger sprayer comprising a tubular nozzle bushing and a nozzle cap rotatable on the bushing. The nozzle cap has an end wall with a swirl chamber formed on the rear face thereof offset from the axis. The swirl chamber has an orifice directed out the front of the cap. This orifice is surrounded by a foaming sleeve. A second orifice with its own swirl chamber is positioned forward of the first orifice so that the spray cone emanating from the said other orifice does not hit the foaming sleeve. The bushing and the cap selectively connect liquid from the delivery tube to the swirl chamber for one or the other orifices.